I think he's in Australia, (the B23E is a big hint, the user name is another) so his car has reverse pattern e-codes (suitable for RHD) Whatever type of lights are involved, the suggestion to make sure the ground connections are clean and tight is a good one. Another possibilty, as these are bulb type headlights (non-sealed) is that the reflectors are dull, tarnished or otherwise deteriorated. If that's the case, replacement is probably the only satisfactory answer, as cleaning the reflectors is just about impossible. (it is a very fragile surface coating)